<p><b>@mmd-osm</b> commented on this pull request.</p>

<hr>

<p>In <a href="https://github.com/openstreetmap/openstreetmap-website/pull/2462#discussion_r362107896">app/mailers/notifier.rb</a>:</p>
<pre style='color:#555'>>        @author = @from_user
 
       attach_user_avatar(comment.user)
 
+      headers["In-Reply-To"] = @ref
+      headers["References"]  = @ref
</pre>
<p>Good point, added a new helper method now.</p>

<p style="font-size:small;-webkit-text-size-adjust:none;color:#666;">—<br />You are receiving this because you are subscribed to this thread.<br />Reply to this email directly, <a href="https://github.com/openstreetmap/openstreetmap-website/pull/2462?email_source=notifications&email_token=AAK2OLM3ULJYJ6DLURR7WLLQ3JWKDA5CNFSM4JZ3T732YY3PNVWWK3TUL52HS4DFWFIHK3DMKJSXC5LFON2FEZLWNFSXPKTDN5WW2ZLOORPWSZGOCQNBBVY#discussion_r362107896">view it on GitHub</a>, or <a href="https://github.com/notifications/unsubscribe-auth/AAK2OLMERJQLCEEICGB3TQDQ3JWKDANCNFSM4JZ3T73Q">unsubscribe</a>.<img src="https://github.com/notifications/beacon/AAK2OLKQPEEB5UP32E3C75LQ3JWKDA5CNFSM4JZ3T732YY3PNVWWK3TUL52HS4DFWFIHK3DMKJSXC5LFON2FEZLWNFSXPKTDN5WW2ZLOORPWSZGOCQNBBVY.gif" height="1" width="1" alt="" /></p>
<script type="application/ld+json">[
{
"@context": "http://schema.org",
"@type": "EmailMessage",
"potentialAction": {
"@type": "ViewAction",
"target": "https://github.com/openstreetmap/openstreetmap-website/pull/2462?email_source=notifications\u0026email_token=AAK2OLM3ULJYJ6DLURR7WLLQ3JWKDA5CNFSM4JZ3T732YY3PNVWWK3TUL52HS4DFWFIHK3DMKJSXC5LFON2FEZLWNFSXPKTDN5WW2ZLOORPWSZGOCQNBBVY#discussion_r362107896",
"url": "https://github.com/openstreetmap/openstreetmap-website/pull/2462?email_source=notifications\u0026email_token=AAK2OLM3ULJYJ6DLURR7WLLQ3JWKDA5CNFSM4JZ3T732YY3PNVWWK3TUL52HS4DFWFIHK3DMKJSXC5LFON2FEZLWNFSXPKTDN5WW2ZLOORPWSZGOCQNBBVY#discussion_r362107896",
"name": "View Pull Request"
},
"description": "View this Pull Request on GitHub",
"publisher": {
"@type": "Organization",
"name": "GitHub",
"url": "https://github.com"
}
}
]</script>